ML-GS: Module Lattice-Based Group Signature Scheme

Abstract With the rapid growth of online users, protecting user privacy in access control scenarios has become a critical challenge in the field of information security. Group signatures serve as a fundamental cryptographic primitive that enables users to sign on behalf of a group, providing anonymity while supporting traceability of signers. However, traditional group signature schemes, which rely on number-theoretic assumptions vulnerable to quantum algorithms, face significant security threats in the advent of quantum computing. In this paper, we propose a module lattice-based group signature scheme (ML-GS). ML-GS leverages FIPS 204 standard, a recently standardized signature scheme by the National Institute of Standards Technology (NIST), and integrates a dualrejection-sampling signature mechanism with the K-PKE encryption scheme from FIPS 203 standard, forming a “sign-hybrid-encrypt” hybrid structure to ensure both efficiency and traceability. In the key generation phase, we introduce a module Gaussian preimage sampling algorithm that reduces public key size and supports dynamic user enrollment. The security of ML-GS is formally proven in the random oracle model under the Module Learning with Error (MLWE) and Module Short Integer Solution (MSIS) assumptions. Experimental results demonstrate that, compared to existing scheme with equivalent security level, the ML-GS scheme achieves significant improvements in both time and storage overhead.